Should Genetic Testing for extra chromosomes (down syndrome) be allowed?
Down syndrome is the chromosomal fault where you have 47 somatic cells and two ‘21’ cells. What is the point for screening for genetics faults like Down syndrome?
Down syndrome is the most common chromosomal abnormality to result in a live birth and can have a major impact on a family; prenatal screening has been offered for some time. As with all prenatal screening there is the risk of false results (where the foetus is fact chromosomally normal but the screen shows increased risk of an abnormality), of miscarriage induced by the testing itself, as well as the ethical and moral questions that can be challenging and uncomfortable to contemplate, let alone be called to make a decision regarding where you stand.
PGD is most commonly used for four kinds of tests. These include tests for: 1) genetic abnormalities, such as single-gene defects that cause diseases like cystic fibrosis; 2) aneuploidy—a chromosome problem, such as Down syndrome, that is caused by an extra or missing chromosome; 3) translocation, in which pieces of one or more chromosomes have switched places, causing carriers to be at increased risk of infertility, miscarriage, stillbirth, and/or having a child with birth defects; and 4) choosing the sex of the embryo. During in vitro fertilization (IVF), after a woman's ovaries are stimulated using hormones, some eggs are extracted and fertilized in the laboratory with sperm. In PGD, a cell is removed from each of these embryos when they have reached the eight-cell stage (after three days of development). Only those embryos that are deemed healthy or of the preferred sex will be transferred into the woman's uterus for development. Since its introduction in 1990, PGD has been widely used to prevent the development of embryos with mutations for lethal diseases such as cystic fibrosis and Huntington's chorea, and to prevent recurrent pregnancy loss.
Down syndrome is the chromosomal fault where you have 47 somatic cells and two ‘21’ cells.
What is the point for screening for genetics faults like Down syndrome?
Down syndrome is the most common chromosomal abnormality to result in a live birth and can have a major impact on a family; prenatal screening has been offered for some time. As with all prenatal screening there is the risk of false results (where the foetus is fact chromosomally normal but the screen shows increased risk of an abnormality), of miscarriage induced by the testing itself, as well as the ethical and moral questions that can be challenging and uncomfortable to contemplate, let alone be called to make a decision regarding where you stand.
PGD is most commonly used for four kinds of tests. These include tests for: 1) genetic abnormalities, such as single-gene defects that cause diseases like cystic fibrosis; 2) aneuploidy—a chromosome problem, such as Down syndrome, that is caused by an extra or missing chromosome; 3) translocation, in which pieces of one or more chromosomes have switched places, causing carriers to be at increased risk of infertility, miscarriage, stillbirth, and/or having a child with birth defects; and 4) choosing the sex of the embryo.
During in vitro fertilization (IVF), after a woman's ovaries are stimulated using hormones, some eggs are extracted and fertilized in the laboratory with sperm. In PGD, a cell is removed from each of these embryos when they have reached the eight-cell stage (after three days of development). Only those embryos that are deemed healthy or of the preferred sex will be transferred into the woman's uterus for development.
Since its introduction in 1990, PGD has been widely used to prevent the development of embryos with mutations for lethal diseases such as cystic fibrosis and Huntington's chorea, and to prevent recurrent pregnancy loss.